Method and system of measuring surface temperature

Abstract

Provided is a measuring method capable of accurately measuring the surface temperature of a surface to be measured, uninfluenced by the emissivity distribution of the surface to be measured. A surface to be measured having an emissivity distribution, a radiometer that measures a radiance distribution of the surface to be measured, and an auxiliary heat source installed in a specular reflection position from the radiometer with respect to the surface to be measured are prepared, radiances of two places having different emissivities of the surface to be measured are measured at two different auxiliary-heat-source temperatures, a reflectance ratio of the two places having the different emissivities is calculated on the basis of two measured radiances of the two places having the different emissivities, and temperature of the surface to be measured is obtained using reflectance ratio and measured radiances of the two places having different emissivities.

The invention claimed is: 
     
       1. A method of measuring surface temperature, comprising:
 preparing a surface to be measured that has an emissivity distribution, a radiometer that measures a radiance distribution of the surface to be measured, and an auxiliary heat source installed in a specular reflection position from the radiometer with respect to the surface to be measured; 
 measuring a first radiance of a first place of the surface to be measured and a second radiance of a second place of the surface to be measured, wherein the second place has an emissivity different from an emissivity of the first place, and the second radiance is measured at an auxiliary-heat-source temperature the same as an auxiliary-heat-source temperature at which the first radiance is measured; 
 measuring a third radiance of the first place of the surface to be measured, and a fourth radiance of the second place of the surface to be measured, and the fourth radiance is measured at an auxiliary-heat-source temperature the same as an auxiliary-heat-source temperature at which the third radiance is measured and is different from an auxiliary-heat-source temperature at which the first radiance is measured; 
 calculating a reflectance ratio between the first place and the second place on the basis of the first radiance, the second radiance, the third radiance and the fourth radiance; 
 after calculating the reflectance ratio, measuring a fifth radiance of the first place of the surface to be measured, and a sixth radiance of the second place of the surface to be measured, wherein the sixth radiance is measured at an auxiliary-heat-source temperature the same as an auxiliary-heat-source temperature at which the fifth radiance is measured; and 
 obtaining a temperature of the surface to be measured, using the reflectance ratio, the fifth radiance and the sixth radiance. 
 
     
     
       2. A system of measuring surface temperature, comprising:
 a surface to be measured that has an emissivity distribution; 
 a radiometer that measures a radiance distribution of the surface to be measured; and 
 an auxiliary heat source installed in a specular reflection position from the radiometer with respect to the surface to be measured, 
 wherein a first radiance of a first place of the surface to be measured is measured, and a second radiance of a second place of the surface to be measured is measured, wherein the second place has an emissivity different from an emissivity of the first place, and the second radiance is measured at an auxiliary-heat-source temperature the same as an auxiliary-heat-source temperature at which the first radiance is measured, 
 wherein a third radiance of the first place of the surface to be measured is measured, and a fourth radiance of the second place of the surface to be measured is measured, and the fourth radiance is measured at an auxiliary-heat-source temperature the same as an auxiliary-heat-source temperature at which the third radiance is measured and is different from an auxiliary-heat-source temperature at which the first radiance is measured, 
 a reflectance ratio between the first place and the second place on the basis of the first radiance, the second radiance, the third radiance and the fourth radiance, 
 after the reflectance ratio is calculated, a fifth radiance of the first place of the surface to be measured is measured, and a sixth radiance of the second place of the surface to be measured is measured, wherein the sixth radiance is measured at an auxiliary-heat-source temperature the same as an auxiliary-heat-source temperature at which the fifth radiance is measured, and 
 a temperature of the surface to be measured is obtained using the calculated reflectance ratio, the fifth radiance and the sixth radiance. 
 
     
     
       3. The system of measuring surface temperature according to  claim 2 , wherein the radiometer that measures a radiance distribution is a thermal imaging device or a one-dimensional scanning radiometer.